The manufacture of tires is significantly complicated by the imparting of decorative bands into a tire sidewall to form a "white sidewall" tire. Presently, this is accomplished by fabrications using the extrusion and calendering of a number of black and white components which are subsequently combined into a decorative sidewall preassembly. All of the tire components, including the tire sidewall preassembly, are then applied in sequence to the tire building drum to form the green or uncured tire. Following the tire curing operation, the decorative sidewall side of the tire is carefully ground and buffed to expose the decorative sidewall area which was previously protected by a cover strip. These complex steps detrimentally effect the efficiency of the tire manufacturing process. Further, many interfaces produced in construction of the decorative sidewall tire effect the structural integrity of the tire and its durability and performance on the road.
It is generally known in the tire industry that the tire carcasses used for forming a blackwall tire are different from those employed in manufacturing tires having decorative features or "white sidewalls" thereon. Further, modern tires are designed with increasingly thinner sidewalls, such that the decorative portion of the sidewall is becoming an increasingly significant part of the tire sidewall structure itself. Since the decorative portion is typically less than optimum as a structural element, it is becoming increasingly difficult to manufacture modern tires having sidewalls with decorative features thereon. Previously known tires with decorative sidewalls have been characterized by a plurality of boundaries defining the different layers of the decorative structure, each boundary presenting an area for the development of a potential defect.
To obviate the shortcomings of the prior art, it has been proposed to replace the previously known sidewall decorative features with appliques of polymeric paint applied to stock blackwall tires after the curing operation on the tire. Such structures and techniques are taught in U.S. Pat. Nos. 4,767,481, 4,684,420, 4,699,193, and 4,684,431, all assigned to Bridgestone/Firestone, Inc. The appliques of these patents are quite thin, on the order of 0.003 inch and, accordingly, susceptible to damage by scrapping, scuffing, and the like. While the appliques are designed to be scuff resistant, and the tire receiving such appliques is configured to protect the same from scuffing, the inherent thin nature of the appliques gives rise to concern over damage resulting from use.
In the past, some attempts have been made to manufacture elastomeric appliques for use in the manufacture of whitewall tires. However, such prior techniques have proven to be time consuming and costly. Previously, single rings of an elastomeric material have been extruded upon a carrier for placement in a tire mold and for transfer by vulcanization to the tire during the curing operation. However, these prior attempts have not demonstrated an ability to be cost effective and reliable. Accordingly, there is a need for an automated method of producing whitewall appliques for vulcanization to a tire during the curing operation.